Redox-Induced Change in the Ligand Coordination Mode

The reaction of cobalt­(II) pivalate with a spin-labeled Schiff base (HL1) in organic solvents formed trinuclear complex [Co3(Piv)2L12L22]·Solv (Solv is Me2CO and/or C7H16 and CH3CN) containing both nitroxide L1 and the product of its single-electron reduction, nitrone L2. The formation of [Co3(Piv)2L12L22] was a consequence of an unusual phenomenon, which we called “redox-induced change in the ligand coordination mode”. A reduction of L1 to L2 led to a change in the set of donor atoms and even in the size of the metallocycle. This phenomenon was also found for mononuclear [CrL12L2] and [FeL12L2]·Me2CO.